The present invention relates to a retention device used to maintain components of a mechanical assembly in an assembled relation. The invention finds particular usefulness in retaining various components, such as collars, washers and other apertured parts, on a complimentary component, such as a stud, pin, bolt or screw.
It has been known for sometime that it is desirable to assemble various components in an early manufacturing operation and then to transport the assembly to other locations for inclusion in other machines, articles, or more complex assemblies. By way of example, it is known to assemble washers onto complimentary bolts prior to using the bolt with a mating threaded fastener in a later operation. Another example is the preassembly of crimp collars onto crimping pins prior to use of the crimp assembly in the field.
When this preassembly technique is employed, it is important to insure that the assembled components remain assembled until used in later manufacturing or fabrication operations. As a result, various retaining devices have been used in the past and are disclosed, for example, in U.S. Pat. Nos. 5,518,768 and 6,025,019.
Another prior art technique has been employed in which a hot melt resin is applied in liquid to the interior of the apertured component and allowed to cool in place to form a retention element, one that relies primarily on compressive forces to maintain the two components in assembled relation. In this prior art technique, the retention element takes the form of a small rounded lump or mound, and it has been found that a rounded retention element geometry suffers from disadvantages. Most notably, such rounded elements do not permit sufficient differential in the forces required for installation versus disassembly of the assembly components.
There is a need for a retention element with more precise dimensioning and with a configuration that permits assembly of the two components with relatively low force when compared with the force required for disassembly of the components.